1. Field of the Invention
The present invention relates to a method, an apparatus, and a computer readable medium thereof for enabling an Internet extension to ring a conventional extension. More particularly, the present invention relates to a method, an apparatus, and a computer readable medium thereof for enabling an Internet extension to ring a conventional extension without the need of an expensive IP-Private Branch Exchange (IP-PBX).
2. Descriptions of the Related Art
In the past, conventional telephones/extensions of conventional telecommunication frameworks have been applied in business entities for communications with external customers/intra-company communications. A conventional telecommunication framework can be implemented by a private branch exchange (PBX). The conventional telecommunication framework exchanges voice data outwards via a public telephone switch network (PTSN; e.g., ChungHwa Telecom), and is connected inwards to conventional extensions within the company.
PTSN has a circuit switch nature. In other words, during a communication process between two parties, a private talking circuit is established between the respective conventional telephones of both parties via a telephone line, while other parties are not allowed to transmit voice data via this telephone line. For frequent communications between different sub-companies or with external customers, a company must apply to ChungHwa Telecom for a number of telephone lines to prevent failure of establishing a talking circuit due to busy lines. Consequently, the company has to pay an appreciable amount of money for the number of telephone lines. Thus, developers have tried to reduce the communication fees to drop the overall operational costs. Accordingly, voice over IP (VoIP) technology has been developed with costs considered.
VoIP is a technical solution that transmits/receives digitalized voice packets via the Internet. As a conventional telephone which allows the connection of a number of extensions, the VoIP telephone also allows the connection of a number of Internet extensions via an IP-PBX. Unlike conventional telephones/extensions that are restricted within the reach of telephone lines, the VoIP telephones/extensions can be installed at any place where the Internet is accessible, so they can be deployed across a wider area.
Nowadays, many companies have established an enterprise telephone network that combines conventional extensions and Internet extensions together to accommodate both the legacy conventional extensions and the lower-cost Internet extensions. However, enabling conventional extensions and Internet extensions in the enterprise telephone network to ring each other is still an important issue.
FIG. 1 illustrates an enterprise telephone network 1 incorporating both conventional extensions and Internet extensions in prior art. The enterprise telephone network 1 comprises a PTSN 15, a hybrid IP-PBX 11, an Internet 13, conventional extensions 14a, 14b and Internet extensions 12a, 12b. The hybrid IP-PBX 11 is an upgraded version of conventional PBX hardware, which allows the Internet extensions 12a, 12b to ring conventional extensions 14a, 14b via the Internet 13 and the hybrid IP-PBX 11. On the other hand, the Internet extensions 12a, 12b are also able to make outside calls via the Internet 13, the hybrid IP-PBX 11 and the PTSN 15. Unfortunately, the hybrid IP-PBX 11 has a prohibitive price of tens to hundreds of millions of New Taiwan dollars, which can be afforded by only few enterprises.
Accordingly, it is important to provide a solution that can enable an Internet extension to ring a conventional extension at a lower cost while still maintaining the quality of connection.